The EU-Turkey refugee deal just took another big hit

Hansjoerg Haber, the Head of European Union Observers Mission in Georgia, speaks during an interview with Reuters in Tbilisi December 12, 2009. REUTERS/David Mdzinarishvili ANKARA (Reuters) - The European Union's top envoy to Turkey has resigned, an official from his delegation said on Tuesday, a month after he was summoned by Turkey's foreign ministry over comments critical of Ankara's handling of a landmark migration deal.

Hansjoerg Haber's resignation comes amid fraught relations between the EU and Ankara, with Brussels desperate to keep Turkey's cooperation in stemming the flow of migrants to Europe but critical of its deteriorating record on rights and freedoms.

"We confirm that Haber has resigned. We are not in a position to comment on the reason at the moment," the official in the EU delegation in Ankara told Reuters. The European Commission had no immediate comment.

Haber was summoned by Turkey's foreign ministry in May to complain about comments he made about the migration deal.

Turkish officials took offense at his use of an unflattering German saying, cited in local newspapers, to describe how a plan to ease visa restrictions for Turks traveling to Europe, part of the wider migrant deal, had run into problems.

Turkey and the EU have been discussing visa liberalization since 2013 and agreed in March to go ahead with it as part of the deal to halt illegal immigration from Turkey to the EU.

But progress stalled when Brussels insisted that Ankara must also reform its tough anti-terror laws for another part of the accord - further talks on EU membership for Turkey - to resume. Turkey said that was out of the question.